Acute effects of putative cocarcinogens and tumor promoters were investigated on cultured human esophageal epithelial cells in serum-free LHC-8 and 199 media with 10% fetal calf serum. The effects were evaluated on clonal growth rate (CGR), cross-linked envelope (CLE) formation, and the enzymatic activities of ornithine decarboxylase (ODC) and plasminogen activator (PA). 12-0-Tetradecanoylphorbol-13-acetate (TPA) and the other compounds were inhibitory to clonal growth. None of the compounds induced CLE formation under the conditions used. TPA significantly induced ODC in media 199 but inhibited it in LHC-8 media. Capsaicin induced ODC in both media. TPA and capsaicin induced PA in both media. The other compounds did not change or rather decreased ODC and PA activities.